Novel 16-ketals of 16-keto-17-deoxyestrone and derivatives thereof



United States Patent 3,138,590 NOVEL 16-KETALS 0F 16-KETO-17-DEOXY- ESTRONE AND DERIVATIVES THEREOF Leland L. Smith, Malvern, Pa., assignor to American Home Products Corporation, New York, N.Y., a corporation of Delaware No Drawing. Filed Aug. 24, 1962, Ser. No. 219,130

10 Claims. (Cl. 260-239.55)

This invention relates in general to a novel series of 16-ketals of 16-keto-17-deoxyestrone, and ethers and esters thereof. More particularly the invention relates to certain 3-alkyl ethers and lower carboxylic acid esters of 16-keto-17-deoxyestrone, methods of preparing the same and pharmaceutical compositions comprising these.

In general the novel compounds of the invention may be represented by the following general structure:

wherein R represents a substituent selected from the group consisting of hydrogen, lower alkyl, lower cycloalkyl, lower alkenyl, lower aralkyl, and acyl; and X represents a member selected from the group consisting of alkylenedioxymethylene, alkylenethioxymethylene and alkylenedithiomethylene.

In the above definition the term lower alkyl as employed refers to those alkyl groups having from about 1 to 20 carbon atoms, and, more particularly, to those having less than about 10 carbon atoms. The alkyl group may be normal or branched in structure though the normal chain is generally preferred. Some examples of these alkyl groups would be methyl, ethyl, propyl, butyl, isopropyl, isobutyl, pentyl, octyl, dodecyl, and cetyl to name a few of such substituents. The term lower cycloalkyl refers to that substituent wherein the carbon atoms are joined in a carbocyclic ring which is generally a5 or 6 membered ring but which may contain a smaller or larger number of carbon atoms subject to the practical limits of stability of such structures. Cyclohexyl would be an example of a preferred member of this class of substituents. The term lower aralkyl refers in general to an alkyl group substituted by an aromatic ring structure, said alkyl group having from about 1 to 20 carbon atoms. An example of this type of substitution would be benzyl, phenylethyl, phenylisopropyl, and the like. By the term acyl as employed'herein is intended the mono-, di-, or poly-carboxy acid radical derived from a saturated or unsaturated organic acid by removal of the hydroxyl group. Such radicals as the alkanoyl radicals of corresponding acids such as acetyl, propionyl and butyryl derived from acetic, propionic, and butyric acids and the like would therefore fall within the scope of this class of substituent. Aryl carboxylic acids, as benzoic acid, are also to be included. By the term lower alkenyl as it is employed herein it is intended to refer to those unsaturated hydrocarbon radicals containing at least one double bond in the chain such as allyl, vinyl and the like. In the present usage this term embraces all'such radicals having less than 20 carbon atoms and preferably less than about 10 carbon atoms.

An essential portion of this novel structure is the substitution indicated by X in the 16-position of the steroid molecule. It is intended by the definition of alkylenedioxymethylene as employed to define X to embrace such ketals containing up to about 10 carbon atoms ice but preferably not more than about 4 carbon atoms. Bythe term alkylenethioxymethylene it is intended to include those ketals where one oxygen atom of the structure has been replaced by a sulfur atom. In a corresponding manner the term alkylenedithiomcthylene as it is employed herein refers to those ketals wherein both oxygen atoms have been replaced by sulfur atoms.

As specific instances of. some of the. compounds included within the scope of the invention one may men-- tion: 16,16 ethylenedioxy 3 methoxyestra 1,3,5'(l0)- triene, 16,16 trimethylenedioxy 3 cyclopentyloxyestra 1,3,5(10) triene, 16,16 ethylenethioxyestra- 1,3,5(10) trien 3 01, 16,16 ethylenedioxy 3 acetoxyestra 1,3,5 (10) triene, 16,16 ethylenedithio 3- ethoxyestra 1,3,5(l0) triene, 16,16 ethylenedioxy 3- benzoyloxyestra 1,3,5 (10) triene, 16,16-ethylenedioxy- 3 butyoxyestra 1,3,5 (10) triene, 16,16-ethylenedioxy- 3 allyloxyestra 1,3,(10) triene, 16,16-ethylenedioxy- 3 cyclohexyloxyestra 1,3,5 (10) triene, 16,16 ethylenedioxy 3 propionoxyestra 1,3,5(10 triene, 16,16- trimethylenedioxy 3 allyloxyestra 1,3,5 (10) triene, 16,16 ethylenethioxy 3 acetoxyestrai 1,3,5(l0)- triene, 16,16 ethylenedioxy'- 3 -benzyloxyestra -1,3, 5(1'0)-triene, etc.

The compounds of the invention are useful in the field of experimental pharmacology as well as beingvaluable as intermediates for further steroid synthesis in preparing new steroidal compounds. In addition, many of the compounds of the invention have been found to demonstrate high antilipemic properties coupled with low feminizing action. Also, besides having capacity to regulate blood lipids, the compounds are useful for their general hormonal effect, particularly in the female. Therefore many of the compounds would be expected to exhibit. utility in those areas where estrogensare employed, such as female hypogonadism, amenorrhea, dysmenorrhea. metrorrhagia, ovulation block and contraception, pregnancy maintenance, arteriosclerosis, osteoporosis, mono-- pausal symptons, infertility, regulation of water balance, functional uterine bleeding, and the like.

The novel compounds of the invention may be prepared by means of one of the general methods outlined or g .(fl l fli In each of the above cases the known-compormds 16-keto-17-deoxyestrone (I), 3-alkoxy' (illustrated by 3 methoxy)-16-keto-17-deoxyestrone (II), and 3-acyloxy (illustrated by acetoxy)-16-keto-17-deoxyestrone (III) are ketalized by treatment with a ketalizing agent such as an alkylene glycol and an acid such as p-toluenesulfonic acid in the presence of an inert solvent such as benzene or the like. As a result the 16-ketone is transformed into the corresponding 16-ketal analog. In a similar manner in a 3-substituted l6-ketone wherein the hydrocarbon moiety of the ether function is comprised of aralkyl, alkenyl or cycloalkyl, the same type of reaction will occur to give the final products of the invention having those particular functional groups in the 3-position.

Alternately .the 16-keta1 (I') may be prepared and then alkylated at the 3-hydroxyl position or acylated at the 3-hydroxyl position to produce the products 3-alkyl ether 16-ketal (II) and the 3-ester l6-ketal (111') respectively.

o w m In those cases wherein the 16-substituted hemithioketal is desired instead of the alkylenedioxymethylene type a reagent such as Z-mercaptoethanol may be substituted for the alkylene glycol in the ketalization. Alternately where the dithioketal is desired a reagent such as ethanedithiol may be substituted for the alkylene glycol in the ketal formation.

In the above mentioned reactions involving ketalization, the reaction is preferably carried out at the refluxing temperature of the solvent until reaction is completed.

The novel compounds of the invention may be admixed and administered in combination if desired with a large number of compatible diluents, carriers and the like to form a pharmaceutical compound. Such wellknown carriers as mineral or vegetable oil or a lower aliphatic alcohol may be used where injectables are to be prepared. Glycerine or the like may be used where the compound is to be administered as a syrup. Carboxymethylcellulose, starches, sugars and the like may be added where tablets or powders are to be employed as a means of administration. The dosage of the compounds will vary with the severity of the ailment and in general can vary from about 0.5 to 100 mg./ kilo of body weight per day depending upon the many factors of the case involved.

The following several examples illustrate the method of preparing some specific compounds of the series. It is of course understood that for a proper legal definition of the invention attention must be directed only to the several appended claims.

EXAMPLE 1 16,16-Ethylenedioxy-3-Meth0xyestra-1,3,5(10)Tricne Reflux together 310 mg. of 3-methoxyestra-l,3,5(10)- trien-l6-one and 70 mg. of p-toluenesulfonic acid in 40 ml. of benzene and 3 ml. of ethylene glycol. After twenty hours stop the heating and wash the mixture with saturated aqueous sodium bicarbonate solution. Wash the benzene layer with water and evaporate the benzene III under vacuum. Dissolve the residue in ether, and crystallize. The first crop of product weighs 170 mg., M.P. l32.5l34.0; the second crop weighs mg, M.P. l31.5-132.5. Infrared spectra show the absence of carbonyl absorption. Thin-layer chromatography shows the presence of the desired product 16,16-ethylenedioxy- 3-methoxyestra-l,3,5(10)-triene.

EXAMPLE 2 16,16-Etl1ylelzedi0xyestra-],3,5 (l0) -Tricn-3-Ol 3-Cycl0pentyl0xy-16,16-Ethylenedi0xyestra- 1,3,5(10)-Triene Dissolve mg. of 16,16-ethylenedioxyestra- 1,3,5 (10)-trien-3-ol in 10 ml. of ethanol containing 3 ml. of cyclopentyl bromide and 100 mg. of sodium hydroxide. Reflux the mixture for 15 hours, and remove the solvents under vacuum. Take up the residue in carbon tetrachloride and wash the carbon tetrachloride solution with 5% sodium hydroxide solution and then with water. Then remove the carbon tetrachloride under vacuum and recrystallize the solid residue from methanol several times to afford the purified product.

EXAMPLE 4 3-Benzyloxy-J6,16-Ethyle/zedi0xyesrra-1,3,5(10)-Triene For 20 hours, reflux a mixture of 1 g. of 16,16-ethylenedioxyestra-l,3,5(l0)-trien-3-ol, 50 ml. of ethanol, 10 ml. of benzyl bromide, and 300 mg. of sodium hydroxide, then remove the solvents under vacuum. Take up the solid residue in carbon tetrachloride and wash the solution first with 5% sodium hydroxide solution, then with water until neutral. Dry the washed carbon tetrachloride solution over anhydrous magnesium sulfate and evaporate under vacuum. Dissolve the solids in hot methanol, concentrate somewhat, and then chill to precipitate the pure product.

EXAMPLE 5 3-14 lIyl0xy-16,16-Ethylenedioxyestra-1,3,5(10)-Triene Reflux a mixture of 500 mg. of 16,16-ethylenedioxyestra-1,3,5(l0)-trien-3-ol, 30 ml. of ethanol, 5 ml. of allyl bromide, and 400 mg. of sodium hydroxide for ten hours, after which time remove the solvents under vacuum. Dissolve the solid residue in carbon tetrachloride and wash the solution with 5% sodium hydroxide solution, and then wash with water. Then remove the carbon tetrachloride under vacuum, and crystallize the solids from methanol. Recrystallization from methanol several times will afford the pure product.

EXAMPLE 6 3-Acetoxy-J 6,]o-Etlzylenedioxyestra-l,3,5 (10) -Triene Reflux a solution of 100 mg. of 16,16-ethylenedioxyestra-l,3,5(l0)-trien-3-ol in 10 ml. of dry pyridine with 3 ml. of acetic anhydride. After 20 hours remove the solvents under vacuum and crystallize the semi-solid residue from acetone. Recrystallize from acetone containing hexane, thus obtaining the pure product.

5 EXAMPLE 7 16,1 6-Trimethylenedioxyestra-1,3,5 (10) -Trien-3-0l EXAMPLE 8 16,16-Ethylenethioxyestra-J,3,5-(10) -Trien-3-Ol Reflux a solution of 100 mg. of 3-hydroxy-1,3,5(10)- trien-16-one in 30 ml. of benzene with 5 ml. of 2-mercaptoethanol and 10 mg. of p-toluenesulfonic acid. After 12 hours (cool the mixture, wash with saturated sodium bicarbonate solution and then with Water, and finally evaporate under vacuum. Dissolve the residue in methanol, concentrate somewhat, and chill to cause precipitatation of product. The pure product may be recovered by filtration.

EXAMPLE 9 16,16-Ethylenedithi-3-Meth0xyestra-1,3,5(10)-Triene Dissolve 100 mg. of 3-methoxyestra-l,3,5(10)-trien-16- one in 10 ml. of chloroform and add 2 ml. of ethanedithiol. Cool the mixture in an ice bath at and maintain at 5 over a period of three hours, during which anhydrous hydrogen chloride should be passed through the solution. Then remove the solvents under vacuum, and crystallize the residue from acetone containing hexane. Recrystallization may be accomplished from methanol, thus affording the pure product.

6 We claim: 1. A compound having the structure:

wherein R represents a substituent selected from the group consisting of hydrogen, lower alkyl, lower cycloalkyl of up to 6 carbon atoms, lower alkenyl, lower aralkyl, lower alkanoyl and benzoyl; and X represents a member selected from the group consisting of lower alkylenedioxymethylene of up to 4 carbon atoms, lower alkylenethioxymethylene of up to 4 carbon atoms and lower alkylenedithiomethylene of up to 4 carbon atoms.

2. A compound according to claim 1 wherein X represents lower alkylenedioxymethylene of up to 4 carbon atoms and R represents lower alkyl.

3. 16,16-ethylenedioxyestra-1,3,5 10)-trien-3-ol.

4. 3 cyclopentyloxy 16,16 ethylenedioxyestra- 1,3,5( 10) -triene.

5. A compound according to claim 1 wherein X represents lower alkylenedioxymethylene of up to 4 carbon atoms and R represents lower alkenyl.

6. 3 allyloxy 16,16 ethylenedioxyestra 1,3,5(10)- triene.

7. 3 acetoxy 16,16 ethylenedioxyestra 1,3,5 (10)- triene.

8. 16,16-trimethylenedioxyestra-1,3 ,5 10) -trien-3-ol.

9. 16,l6-ethylenethioxyestra-1,3,5(10)-trien-3-ol.

10. 3-methoxy-16,16-ethylene dioxyestra 1,3,5 (10)- triene.

References Cited in the file of this patent UNITED STATES PATENTS Huffman Mar. 29, 1955 OTHER REFERENCES Lowenthal: Tetrahedron, vol. 6, pp. 269-303 (1959). 

1. A COMPOUND HAVING THE STRUCTURE: 